AUTOBOTS Prowl, Wheeljack and Arcee were in the original line up along with Optimus Prime, Bumblebee, Ironhide, Ratchet and Jazz. Prowl was featured in the script, but as the writers loved the subversiveness of a Decepticon police car (which became Barricade), he was removed in favor of him. Arcee was initially set to be in the 2007 film, but due to negative fan reaction and to the fact that there was not enough time in the movie to explain the presence of a "female" in a robotic race, she was dropped from the script and replaced with Ironhide. It is unknown why Wheeljack was dropped from the film. Ultra Magnus and Hot Rod were also considered for the 2007 movie.
DECEPTICONS Soundwave, Ravage, Laserbeak, Rumble, Skywarp, Wreckage and Shockwave were in the original line up along with Megatron, Starscream, Barricade, Blackout, Bonecrusher, Brawl, Scorponok and Frenzy. Soundwave was set to appear as a helicopter in the movie, but the helicopter's with the eventual helicopter character rechristened as Vortex, then finally Blackout. Soundwave was considered as a spying boombox on Air Force One, able to transform into a small robot, but eventually, this character was amended to being Frenzy, with Don Murphy stating that Soundwave will be reserved for a future sequel, until they can "do him right". A character named Wreckage, with a M1126 Stryker ICV as his alt mode, had been designed, but eventually didn't get used in the movie, writers Roberto Orci and Alex Kurtzman included the character in one of their drafts of the script, and concept art was even created for it. It is uknown why Shockwave, Ravage, Rumble, Laserbeak and Skywarp were dropped but Shockwave does appear in the videogame and Laserbeak was featured in the Sector Seven viral marketing web site featured several videos recording supposed evidence of Transformers on Earth. Director Michael Bay also considered a character turning into an aircraft carrier (Tidal Wave), which was dropped for cost reasons.
The cancelled characters from this movie that are featured in the sequel Transformers: Revenge of the Fallen are Arcee, Soundwave and Ravage.